Yeah, same. My brother and I play under the same internet connection, but I'm the only one that gets the 90006 error. Tried using another computer, but same issue. It started happening yesterday around 9am PDT, and I wasn't able to actually play until 5:30pm PDT or so. I played until 11:30pm or so, then got booted with 90006.

I can login to my other character in Goblin without any problems. Just can't login to my main on Jenova.
Restarted computer, router, modem like you did - still got the error 90006. Sigh. Happening this morning again too.